Former Prime Minister Tony Abbott has urged European nations to tighten their borders and for a ground war against Islamic State in his first speech since losing the Liberal leadership.

Speaking at an event at Guildhall, London on Wednesday morning (AEDT), Mr Abbott praised conservative former British PM Margaret Thatcher, the event’s namesake.

“As Margaret Thatcher so clearly understood over the Falklands, those that won’t use decisive force, where needed, end up being dictated to by those who will.”

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The international fight against the “would-be terrorist empire” of Islamic State, a key policy platform during his term, was discussed at length.

“We’ve helped to contain its advance in Iraq but we haven’t defeated it because it can’t be defeated without more effective local forces on the ground,” Mr Abbott said.

He advised against an “escalating air campaign”, despite initiating Australian air strikes in the Middle East in one of his final acts as PM.

“Perhaps with Western special forces on the ground as well as trainers, in a part of the world that’s such a witches’ brew of danger and complexity and where nothing ever has a happy ending.”

The lecture was part of a charity event that raised money for an organisation dedicated to educating people on Ms Thatcher’s life, legacy and values.

She led the United Kingdom between 1979 and 1990, making her the longest serving British PM of the 20th century.

She became known as the ‘Iron Lady’, an allusion to her uncompromising political approach and leadership style.

Parallels could be drawn between her conservative version of ‘Thatcherism’ politics and Mr Abbott’s views, including support for deregulation and reducing the power and support of trade unions.

“She didn’t just respond to events, she shaped them and in so doing, she changed Britain and she changed the world,” Mr Abbott said on the conservative leader.

In the speech, he also reiterated one of his most recognisable policy platforms – ‘stop the boats’.

With Europe currently experiencing a massive influx of asylum seekers, Mr Abbott said it was the “only truly compassionate thing to do”.

“The countries of Europe, while absolutely obliged to support the countries neighbouring the Syrian conflict, are more than entitled to control their own borders against those who are no longer fleeing a conflict but seeking a better life,” he said.

“This means turning boats around … it means denying entry at the border for people with no legal right to come.

“And it means establishing camps for people who currently have nowhere to go. It will require some force.

“Yet it is the only way to prevent a tide of humanity surging through Europe and quite possibly changing it forever.”

Tickets to the second annual Margaret Thatcher Lecture and Gala Banquet ranged from £195 to £250 ($A415 to $A531).

Mr Abbott followed in the footsteps of British politician Boris Johnson, who gave the first Margaret Thatcher lecture in 2013.

.@TonyAbbottMHR calls on European leaders to close their borders to asylum seekers https://t.co/N86CUI6uWb https://t.co/P3TiMPKKSn

— ABC News (@abcnews) October 27, 2015